Grain tanks of combines commonly have an associated unloader conveyor operable for conveying grain from the grain tank to another location such as to a grain truck or wagon. An unloader conveyor typically includes an elongate, enclosed tubular housing containing a helical auger and is oriented horizontally or at a small acute angle to horizontal. The unloader conveyor is typically pivotally supported in cantilever relation by a lower end of an upstanding or vertical lower unloader conveyor or auger section including an inlet opening disposed in or adjacent to the grain tank. The unloader conveyor is typically pivotable between a stored position extending along the combine, and a sidewardly extending unloading position. The unloader can be of any length, but will typically have a length sufficient to extend just beyond the end of a header of the combine. Grain tanks additionally typically include at least one grain tank conveyor including an auger adjacent to the bottom of the grain tank and extending into the inlet opening of the lower unloader conveyor or auger for conveying grain into the unloader.
The unloader conveyor requires a significant amount of power to operate, with power requirements foreseeably increasing, especially in light of the demand for ever-increasing grain delivery rates by the combine.
Thus, what is sought is a grain unloader system which permits comparable or increased grain delivery rates while simultaneously reducing the amount of power required to operate the system.